Manufacture of artificial silk



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Patented T1923 untrue srnr Elsi our

UMQ'UFEACT'URIE till ARTIFTGIA'L SILK.

lilo Drawing.

To all who m, may concern:

Be it known that l, EMILE Bnonnnnr, a citizen of the Republic of France, residing at Mulhouse, Alsace-Lorraine, France, have invented certain new and useful lm rovements in the Manufacture of Artificia Silk; and l do hereby declare the following to be a full, clear, and exact description of the invention.

According to a suggestion made some time ago by the present applicant, very fine threadsol viscose silk were produced by the fine-spinning process, which allows of very strong precip-itants such as sulphuric acid being employed and of the spinning, from the some viscose, of threads of all fincnesses by means of nozzle apertures possessing the same mean diameter (0.10 mm.), by reason of the concentration of the acid being regulated according to the known rule and the flow oil the viscose being adjusted according to the thickness of the thread to be obtained.

In the manufacture from viscose sillr o'i artificial sillr of about 8 deniers, the method is also lrnown of adding glucose and other organic substances to the acid so as to deprive the acid of its sharpness.

A precipitating bath for viscose threads has adready been suggested, consisting of a crude mixture of carbohydrates, mineral acid or salts of mineral acid and icy-products obtained by hydrolyzing and heating wood or other cellulose-containing materials with mineral acids, with or without the addition of other reagents.

The present invention does not relate to these known methods but assumes tor its starting point the observed fact that the threads obtained by the new fine-spinning process with a highly concentrated acid, often do not possess the requisite degree oi? flexibility and that the fine threads emerging from the nozzle show a strong tendency to knot together in a bunch, which must afterwards he disentangled.

The present invention provides a remedy for this disadvantageous behaviour. l t consists in utilizing, for the maintenance oi the degree of acidity in the spinning bath, instead or pure acid, acid containing in solution hydrolyzed dextrinous substances as hydrolyzed starch or either cellulose or coagulated waste viscose, (the latter forming a troublesome product arising during the filtration and transport of viscose solu- Application filed August t5, run.

Serial lDtQtB lh'.

tions). These products, when dissolved without heating in an excess oil sulphuric acid, give rise to dentrinous products which act in the beneficial manner described.

Example l.--ln a Warm spinning bath, containing 150 grammes Oil sulphur c acid and 370 grammes of sodium sulphate per litre, the usual operation of spinning is can ried out with crude viscose of a maturity represented by 9 sal ammoniac degrees. Supple threads of a brilliant beauty are obtained.

The previous dissolving in the acid oi a quantity of cellulose hydrate wast/e re resented y grammes net weight ha no effect on the qualities of the threads obtained. The excess of neutral salt Na Sl), over the roportion of bisulphate was in itself, so cient to obviate any injurious dissociation.

Example ll.-lin a warm spinning bath, containing 250 grammes of sulphuric acid and only 250 rammes of soda per litre, the same viscose El degrees) is spun in the same way. The threads now obtained possess only a feeble brilliancy. lit however part of the sulphuric acid be present in the bath in the form of a com-pound cellulose sulphur acid containing for instance a net weight of grammes cellulose, then a thread oil brilliant beauty is obtained. The astonishing result of the partial combination ot the eel with the complex organic radicle is thus clearly evidenced.

Example lll lll, in Example ill, the viscose employed be yet" fresh, having a maturity or about ll.5, t e preliminary dissolving oi 80 grammes of cellulose in the acid, in a cold and concentrated condition, and its subsequent dilution with enough water to moire it up to one litre, is inadecpliate tor the production of highly brilliant t reads, it is necessary to dissolve lull grammes of cellulose and even more.

l claim:

I l. A; process of manufacturing very fine threads from viscose, which comprises regal lating the rate or flow of the viscose from the forming nozzle, regulating the concentration of the acid hardening bath in accordance with the thread diameter desired, by increasing the strength of the acid accord ing to the fineness of the threads, the strength of said both being maintained by an aqueous solution of e lilre acid containing decomposed lllt) lhli 2. A procem of manufacturing very fine that had been previously decomposed into threads from viscose which comprises regucellulose hydrate. l latin the rate of flow of the viscose from In testimony that I claim the foregoing the firming nozzle and the concentration of as my invention I have signed my name.

5 the acid hardening bath in accordance with DR- EMILE BRONNERT.

the thread diameter desired, and maintain- Witnesses: in the strength of said bath by an aqueous Animus BnoNNnR'r, SOfiltiOIl of a like acid containing viscose REN1':E BRONNERT. 

